Dispersion head for solids-liquids blender

ABSTRACT

A liquid dispersion head, which is supported on the end of a liquid supply shaft in a container, is rotated at high speed, so as to simultaneously introduce liquid into and effect agitation of dry material introduced into the container. The spray head includes a hub portion, which is mounted on the liquid supply shaft, and a liquid spray and agitating assembly, which is mounted concentrically of the hub portion and defines two or more mutually supporting liquid spray devices spaced axially of the hub portion.

United States Patent Fischer 51 .Jan.18,1972

[54] DISPERSION HEAD FOR SOLIDS- LIQUIDS BLENDER [72] Inventor: John J. Fischer, East Stroudsburg, Pa.

[73] Assignee: The Patterson-Kelley (10., Inc., East Stroudsburg, Pa.

[22] Filed: Nov. 19, 1970 [21] App1.No.: 91,107

[52] US. Cl ..259/3, 259/16, 259/85 [51] Int. Cl. ..B0lf 9/08 [58] Field ofSearch ..259/3,14, 15,16, 21, 22, 259/84, 85

[56] References Cited UNITED STATES PATENTS Fischer ..259/16 Fischer ..259/16 3,362,688 l/l968 Fischer Primary Examiner-Robert W. Jenkins Attorney-Bean & Bean [5 7] ABSTRACT A liquid dispersion head, which is supported on the end of a liquid supply shaft in a container, is rotated at high speed, so as to simultaneously introduce liquid into and effect agitation of dry material introduced into the container. The spray head includes a hub portion, which is mounted on the liquid supply shaft, and a liquid spray and agitating assembly, which is mounted concentrically of the hub portion and defines two or more mutually supporting liquid spray devices spaced axially of the hub portion.

10 Claims, 6 Drawing Figures PATENIED MM 1 8 m2 SHEET 1 BF 3 I NVENTOR. JOHN J. FISC HER ATTOPNE Y5 WENIEU JM 1 81972 SHEET 2 OF 3 @U M MQ ATTORNEYS DISPERSION HEAD FOR SOLIDS-LIQUIDS BLENDER SUMMARY OF THE INVENTION The invention relates to an improved liquid dispersion head characterized as having the capacity for handling large quantities of liquids in continuous blending units and which possesses particular utility in solids-liquids blenders of thegeneral type disclosed in my prior US. Pat. No. 3,362,688.

With prior dispersion head constructions, a great discrepancy normally exists between the solids blending and liquid dispensing capacities of the dispersion head. In this respect it will be understood that the capacity for handling or blending solids increases as the cube of the diameter of the dispersion head, whereas the liquid dispensing capacity of a single orifice or gap extending annularly of the dispersion head increases in direct proportion to such diameter. While an obvious solution is to increase the number of orifices employed in any given dispersion head, it is not practical to provide more than a limited number of orifices of any given point along the dispersion head due to material agitating and liquid distribution consideration.

The above-mentioned problem is solved in accordance with the present invention by providing a dispersion head with multiple sections, each having its own orifices and agitating blades. The construction permits the number of sections, as well as the number of orifices and the widths thereof, to be readily varied, as determined by desired solids-liquids blending operating conditions.

More specifically, the dispersion head of the present invention includes a hub portion, which serves to removably mount the head on the end of a rotatable stub drive shaft; and multisectioned assembly, which is removably supported on the hub portion and serves to define two or more liquid spray and agitating devices spaced axially of the hub portion.

The construction of the hub portion and the liquid spray assembly results in a relatively lightweight construction, as compared with prior, similarly sized dispersion head constructions and thereby serves to minimize bending loads imposed on the bearing supports of the head supporting drive shaft.

Further, the head construction of the present invention results in lower head fabricating costs, due to the identity of parts employed in forming the liquid spray assembly regardless of the number of sections employed. Moreover, reduced costs are achieved by the present head construction, which pennits various sized or spray capacity heads to be quickly and easily mounted on the same drive shaft without the need for modifying same in any way.

DRAWINGS These, as well as other advantages of the invention, will now appear from the following description taken with the accompanying drawings wherein:

FIG. 1 is a side elevational view, partly in section, of a solids-liquids blender showing the dispersion head of the invention installed;

FIG. 2 is a front end view on enlarged scale of the blender of FIG. 1;

FIG. 3 is a fragmentary sectional view on enlarged scale taken on line 3-3 of FIG. 1;

FIG. 4 is a fragmentary sectional view taken on line 44 of FIG. 3'

FIG: 5 is a fragmentary sectional view taken on line 55 of FIG. 4; and

FIG. 6 is a view similar to FIG. 3, but on a reduced scale and showing only the movement of material within the material receiving or feed chamber.

DETAILED DESCRIPTION As by way of reference, the dispersion head of the present invention, which is generally designated as 10, is particularly adapted for use in solids-liquids blenders of the type disclosed in my prior U.S. Pat. No. 3,362,688. Blenders of this type generally comprise a blending or mixing shell or container 20,

which is made of metal, plastic or other suitable material and formed to provide a series of openly intercommunicating truncated tubular sections 22, which are disposed to extend lengthwise of the blender in zigzag relation. The zigzag relationship of the tubular components 22 may be centered in one plane of may exist in any number of radially intersecting planes passing through the center line of rotation of the device, as may be preferred. In any case, the configuration of the container 20 provides in effect, a series of intercommunicating Vshaped chambers.

The container 20 ispreferably mounted for rotation on a tilt table of base member 25by means of trunnion wheels 26 carried by mounting brackets 27. Trunnion wheels 26 engage corresponding trunnion rims 29, which are mounted so that their centers of rotation coincide with the longitudinal centerline of the container as indicated at C.L. (FIG. I). Rotation of the container may be effected by any suitable means, such as a motor and gearbox unit 30 driving through a belt or chain 32 trained around a sprocket 34, which :in turn is mounted on container 20 concentrically of the center line of rotation thereof.

As more fully explained in my above-mentioned prior patent, container 20 tumbles materials and in addition also moves the particles both downstream and upstream, the overall net flow being downstream. The net flow rate through a given machine depends on the rate of feed and the speed of rotation of container 20, and on the angle of tilt at which the rotation axis is set.

The feed inlet end of the container 20 is shown as comprising a cylindrically shaped feed chamber or material receiving drum 35, which is arranged for rotation eccentrically of the center line of container rotation. Feed chamber 35 is formed with a circular feed-receiving opening; 36 through the outer end wall thereof, which is arranged concentrically with the axis of rotation of the container. A loading chute 37 is stationarily mounted upon the base 25 for the purpose of feeding material into feed chamber 35 through opening 36, and a suitable dust seal device 40 is employed to seal the juncture of chute 37 and feed chamber 35 to prevent leakage of material therefrom.

To introduce liquid into the blender, chute 37 may be apertured, as shown in FIG. 4, to accommodate projection therethrough of a stationary tubular housing 44, which is fixed to the chute and rotatably mounts therein a hollow drive shaft 45, as by means of a ball bearing device 46 and a roller bearing device 48. A liquid-dust seal indicated at 49 is preferably provided at the inner end portion of housing 44. At its inner end drive shaft 45 projects into the drum 3S and mounts thereon dispersion head 10 of the present invention, which will hereinafter be described in detail.

A stationary liquid feed tube 52 is arranged within drive shaft 45 for the purpose of feeding liquid under pressure from a suitable source, not shown, through shaft 45 and into head 10. Drive shaft 45 also carries a pulley or sprocket 64, and is hereby arranged to be driven by means of a belt 66 and motor 68 (FIG. I) or other suitable means.

It will be understood that motor 68 rotates dispersion head 10 at high speed, such that it will disperse feed liquid in finely divided spray or film form into the dry feed material; the parts being so dimensioned and arranged that the dispersion head 10 normally resides inside the body of dry material milling around within the feed chamber 35, as indicated in FIG. 6. Hence, the dispersion head will not only disperse finely divided liquid feed material into the dry feed, but it will also agitate or churn the dry material as the: latter flows to and fro in the feed chamber 35, due to disposition of the feed chamber center line eccentrically of its center of rotation.

Now referring particularly to FIG. 4, it will be seen that the dispersion head of the present invention generally includes a hub portion 70, which is supported on shaft 45; and a liquid spray and agitating assembly 72, which is supported on the hub portion.

Specifically, hub portion 70 includes a mounting hub 74, which is provided with a conically shaped through opening 76 adapted to receive a like configured end portion 78 of shaft 45 or fitting fixed to such shaft. Mounting bolts 80 may be employed to fix mounting hub 74 on shaft end portion 78 and tighten the liquid seal or tapered lock formed by the conicallyshaped surfaces thereof. Hub portion 70 also includes a rigid annular flange 82, which extends radially from mounting hub 74; a relatively thin walled cylindrical portion 84, which is fixed to flange 82 and disposed concentrically of mounting hub 74; and an end closure plate 86, which is removably connected to the free end of cylindrical portion 84, as by bolts 88.

As thus constructed, hub portion 70 defines a chamber 90 arranged in flow communication with feed tube 52. it will be understood that upon rotation of head 10, liquid received within chamber 90 forms a thin layer or film on the cylindrical inner surface of cylindrical portion 84, which is thereafter discharged radially through groups of discharge openings 92-94 spaced axially of cylindrical portion 84. The use of groups of relatively small, circular openings insures uniform distribution of liquid in a direction axially of chamber 90.

Hub, 74 flange 82 and cylindrical portion 84 may, if desired, be formed as a one piece metal casting. However, as will be described, hub portion 70 is preferably formed of separate pieces welded or otherwise fixed together.

In the illustrated embodiment of head 10, assembly 72 includes three liquid spray and agitating devices 102-104, which are spaced axially of cylindrical portion 84 in radial alignment with groups of discharge openings 92-94, respectively. Of course, the number of groups of discharge openings will be determined by the number of spray devices, which will in turn be determined by the length of receiving chamber 35 and/or the amount of liquid desired to be added to the material being treated. Whereas, the construction of head .10 admits to providing two or more liquid spray and agitating devices, three or more devices will be employed in most installations.

Devices 102-104 include annularly extending mounting flanges 102a-104b, which cooperate with one or more annularly extending spacer plates 112-114 sandwiched therebetween,so as to define annularly extending liquid spray orifices through which liquid is discharged, as indicated by arrows 116. The separation between the mounting flanges and/or the spacer plates and thus the widths of the several spray orifices is determined by the thicknesses of relatively thin spacer elements 118, through which are passed mounting flange and spacer plate clamping bolts 120, as indicated in FIG. 4. Alternatively, bolts 120 may be replaced by friction fitted key pins and devices 102-104 clamped against mounting flange 102a providing closure plate 86 with an annular rim, which is arranged to clampingly engage mounting flange 104b when bolts 88 are tightened.

For any given number of spray devices, the amount of liquid discharged thereby may be readily controlled by varying the rotational speed of the dispersion head, the number of spacer plates and the spacing between the spacer plates and/or mounting flanges. However, as a practical matter, inasmuch as the fineness of the liquid spray is determined by the width of the spray orifices and the peripheral velocity of head 10, control of the amount of liquid discharged is more readily effected by varying the number of spacer plates and/or spray devices. This can be readily accomplished due to the novel arrangement for supporting the spray and agitating assembly to be hereinafter described.

To augment the dry feed material churning effect hereinafter described, pluralities of radially extending material agitating blades 122 are affixed to mounting flanges l02a-104b by bolts 124 and mounting guide pins 126. As best shown in FIGS. 3 and 4, blades 122 extend radially of the axis of rotation of head 10, but have their free outer ends disposed in planes canted relative to such axis. Thus, upon rotation of head 10, blades 122 effect a particularly vigorous agitating action on the material within receiving chamber 35, and liquid is sprayed into the dry material in those areas of the material subject to maximum agitation. However, it will be understood that where minimum attrition of the material being treated is desired, blades 122 may be omitted.

A particularly important feature of the present invention is the novel arrangement for mutually supporting devices 102-104 and mounting same on hub portion 70. To this end, spray device 102 is fixed for rotation with mounting hub 74, as by forming mounting flange 102a integrally with or otherwise fixing it for rotation with annular flange 82, whereas spray device 103 is fixed for rotation with spray device 102 and spray device 104 is fixed for rotation with spray device 103 by means of bridging sleeves and 132, which join mounting flanges 102b-103a and 103b-104a, respectively. As desired, bridging sleeves 130, 132 may be weld affixed or fonned integrally with their associated mounting flanges.

As will be apparent from viewing FIG. 4, bridging sleeves 130, 132 are disposed concentrically of cylindrical portion 84 and cooperate with mounting flanges 102a and 104b to define annular chamber 134 through which liquid passes from groups of discharge openings 92-94 to the spray orifices defined by devices 102-104. in this connection, an effective fluid seal is formed between mounting flange 104b and the outer surface of cylindrical portion 84 by providing a close sliding fit therebetween. By slip fitting mounting flange l04b on cylindrical portion 84, the former may be easily removed and reinstalled when it is desired to add or remove spacer plates or spacing elements in order to vary the amount of liquid to be sprayed.

Referring to FIGS. 4 and 5, it will be understood that preferably both, but at least one, of spray devices 103, 104 are also fixed for rotation with the free end of cylindrical portion 84 by a keylock arrangement comprising a key bar fixed to cylindrical portion 84, as by screws 142, and cooperating key bar receiving recesses 144 provided in one or more of spacer plates 113, 114. By this arrangement, assembly 72 and cylindrical portion 84 cooperate to resist torsion forces set up during the agitating operation and transfer same directly to mounting hub 74 via rigid flange 82. As a result, each of assembly 72 and cylindrical portion 84 is permitted to be formed of relatively light weight construction in order to minimize the bending loads imposed on the bearings of drive shaft 45. Moreover, this construction requires only a short length of shaft 45 to extend beyond its support bearings into chamber 35, regardless of the number of spray devices employed. This results in greatly reduced bending loads as compared with dispersion head constructions of the type disclosed by my prior patent, wherein each spray device is independently mounted on the drive shaft.

Also, by fixing dispersion head 10 to the end of shaft 45, a dispersion head having any desired number of spray devices may be mounted without the need for modifying the drive shaft in any way, and the dispersion head may be quickly and easily removed as a unit from the drive shaft for purposes of maintenance and adjustment, as desired.

The construction of the present invention also results in low fabricating and assembly costs, due to the identity of parts employed in forming assembly 72, regardless of the number of spray devices employed. Where cylindrical portion 84 is welded to flange 82, even greater economies are achieved, since the only component required to be fabricated in more than one size in order to produce a head having different numbers of spray devices is the cylindrical portion.

Although only one form of the present invention has bee illustrated and described in detail hereinabove, it will be understood that various changes may be made therein without departing from the spirit of the invention.

1 claim:

1. in a solids-liquids blender including a container for receiving material, shaft means for conveying liquid inwardly of said container, a dispersion head mounted on said shaft means inwardly of said container for feeding liquid from said shaft means to said material, and means for relatively rotating said dispersion head and said container to effect agitation of said material, the improvement wherein said-dispersion head comprises in combination:

hub means, said hub means defining a chamber extending axially of said hub means and liquid discharge openings extending radially outwardly from said chamber;

means for mounting said hub means adjacent one end of said chamber coaxially on an end of said shaft means extending inwardly of said container to position said chamber in fluid communication with said shaft means;

a liquid feed assembly; and

means for mounting said assembly on said hub means concentrically outwardly thereof, said assembly including at least two liquid feed means spaced apart axially of said hub means and defining annularly arranged orifices through which liquid discharged through said openings is fed to said material within said container.

2. An improvement according to claim 1, wherein said assembly mounting means includes first means to removably fix a first of said feed means for rotation withsaid hub means adjacent said one end of said chamber and second means to removably fix a second of said feed means for rotation with said hub means adjacent another end of said chamber, and said assembly includes means to fix said second means for rotation with said first feed means.

3. An improvement according to claim ll, wherein said assembly includes at least three feed means, said assembly mounting means includes first means to removably fix a first of said feed means for rotation with said hub means adjacent said one end of said chamber and second means to removably fix at least one of said second and third said means for rotation with said hub means adjacent another end of said chamber, and said assembly includes means to removably affix said third feed means for rotation with said second feed means and said second feed means for rotation with said first feed means.

4. An improvement according to claim 1, wherein said hub means includes a hub portion mounted coaxially on said end of said shaft means, an annular flange fixed to and extending radially from said hub portion, a cylindrical portion fixed to said annular flange concentrically of said hub portion and plate means removably affixed to said cylindrical portion remotely of said annular flange, said hub portion, annular flange, cylindrical portion and plate means bounding said chamber, said openings extending radially through said cylindrical portion, and being arranged in groups spaced axially of said cylindrical portion in radial alignment with said orifices; and said hub mounted means includes a conically shaped through opening arranged axially of said hub portion, a conically shaped surface portion on said end of said shaft means and bolt means for fixing said hub portion onto said shaft means, said conical surfaces being arranged in a friction tight fluid sealed relationship upon tightening of said bolt means.

5. An improvement according to claim 1, wherein said feed means each include first and second annular mounting flanges removably fixed together, said orifices of each said feed means being arranged intermediate said first and second mounting flanges thereof, said first flange of a first of said feed means being mounted adjacent said one end of said chamber, and said assembly including bridging sleeves extending axially between and fixed to second and first flanges of adjacent feed means.

6. An improvement according to claim 5, wherein said feed means each additionally include at least one orifice bounding annular spacer plate clampingly secured intermediate said mounting flanges thereof.

7. in a solids-liquids blender including a container for receiving material, shaft means for conveying liquid inwardly of said container, a dispersion head mounted on said shaft means inwardly of said container for feeding liquid from said shaft means to said material, and means for relatively rotating said dispersion head and said container to effect agitation of said material, the improvement wherein said dispersion head corn rises in combination:

hu means, said hub means including a hub portion mounted coaxially on an end of said shaft means extending inwardly of said container, an annular flange fixed to and extending radially from said hub portion, a cylindrical portion fixed to said annular flange concentrically of said hub portion and plate means fixed to said cylindrical portion remotely of said annular flange, said hub portion, annular flange, cylindrical portion and plate means bounding said chamber, said cylindrical portion having openings extending radially therethrough; means for mounting said hub portion on said end of said shaft means to position said chamber in fluid communication with said shaft means; liquid feed assembly including a series of liquid feed means and bridging means, said feed means defining annularly arranged orifices through which liquid discharged through said openings is fed to said material within said container, each said feed means including first and second annular mounting flanges, and at least one orifice bounding annular spacer plate arranged intermediate said mounting flanges, and a first means of said series having a first mounting flange thereof fixed to said annular flange, said bridging means including sleeve members fixed to said second and first mounting flanges of adjacent feed means to space said feed means axially of said cylindrical portion;

means to removably clamp said mounting flanges and spacer plate in assembled condition;

key means to removably fix at least one other feed means of said series to said cylindrical portion remotely of said annular flange.

8. An improvement according to claim 7, wherein said key means includes a key bar fixed to the radially outer surface of said cylindrical portion and extending axially thereof and key bar receiving recess formed in said spacer plate of said one other feed means.

9. An improvement according to claim 7, wherein said second mounting flange of a last feed means of said series is slideably supported by the radially outer surface of said cylindrical portion to form a liquid seal therewith and to cooperate with said first mounting flange of said first feed means to maintain said assembly concentric of said outer surface of said cylindrical portion.

10. An improvement according to claim 9, wherein said key means includes a key bar fixed to the radially outer surface of said cylindrical portion and extending axially thereof and key bar receiving recess formed in said spacer plate of said one other feed means; said hub mounting means includes a conically shaped through opening arranged axially of said hub portion, a conically shaped surface portion on said end of said shaft means and bolt means for fixing said hub portion onto said shaft means, said conical surfaces being arranged in a friction tight fluid sealed relationship upon. tightening of said bolt means; and said openings being arranged in groups spaced axially of said cylindrical portion in radial alignment with said orifices. 

1. In a solids-liquids blender including a container for receiving material, shaft means for conveying liquid inwardly of said container, a dispersion head mounted on said shaft means inwardly of said container for feeding liquid from said shaft means to said material, and means for relatively rotating said dispersion head and said container to effect agitation of said material, the improvement wherein said dispersion head comprises in combination: hub means, said hub means defining a chamber extending axially of said hub means and liquid discharge openings extending radially outwardly from said chamber; means for mounting said hub means adjacent one end of said chamber coaxially on an end of said shaft means extending inwardly of said container to position said chamber in fluid communication with said shaft means; a liquid feed assembly; and means for mounting said assembly on said hub means concentrically outwardly thereof, said assembly including at least two liquid feed means spaced apart axially of said hub means and defining annularly arranged orifices through which liquid discharged through said openings is fed to said material within said container.
 2. An improvement according to claim 1, wherein said assembly mounting means includes first means to removably fix a first of said feed means for rotation with said hub means adjacent said one end of said chamber and second means to removably fix a second of said feed means for rotation with said hub means adjacent another end of said chamber, and said assembly includes means to fix said second means for rotation with said first feed means.
 3. An improvement according to claim 1, wherein said assembly includes at least three feed means, said assembly mounting means includes first means to removably fix a first of said feed means for rotation with said hub means adjacent said one end of said chamber and second means to removably fix at least one of said second and third said means for rotation with said hub means adjacent another end of said chamber, and said assembly includes means to removably affix said third feed means for rotation with said second feed means and said second feed means for rotation with said first feed means.
 4. An improvement according to claim 1, wherein said hub means includes a hub portion mounted coaxially on said end of said shaft means, an annular flange fixed to and extending radially from said hub portion, a cylindrical portion fixed to said annular flange concentrically of said hub portion and plate means removably affixed to said cylindrical portion remotely of said annular flange, said hub portion, annular flange, cylindrical portion and plate means bounding said chamber, said openings extending radially through said cylindrical portion, and being arranged in groups spaced axially of said cylindrical portion in radial alignment witH said orifices; and said hub mounted means includes a conically shaped through opening arranged axially of said hub portion, a conically shaped surface portion on said end of said shaft means and bolt means for fixing said hub portion onto said shaft means, said conical surfaces being arranged in a friction tight fluid sealed relationship upon tightening of said bolt means.
 5. An improvement according to claim 1, wherein said feed means each include first and second annular mounting flanges removably fixed together, said orifices of each said feed means being arranged intermediate said first and second mounting flanges thereof, said first flange of a first of said feed means being mounted adjacent said one end of said chamber, and said assembly including bridging sleeves extending axially between and fixed to second and first flanges of adjacent feed means.
 6. An improvement according to claim 5, wherein said feed means each additionally include at least one orifice bounding annular spacer plate clampingly secured intermediate said mounting flanges thereof.
 7. In a solids-liquids blender including a container for receiving material, shaft means for conveying liquid inwardly of said container, a dispersion head mounted on said shaft means inwardly of said container for feeding liquid from said shaft means to said material, and means for relatively rotating said dispersion head and said container to effect agitation of said material, the improvement wherein said dispersion head comprises in combination: hub means, said hub means including a hub portion mounted coaxially on an end of said shaft means extending inwardly of said container, an annular flange fixed to and extending radially from said hub portion, a cylindrical portion fixed to said annular flange concentrically of said hub portion and plate means fixed to said cylindrical portion remotely of said annular flange, said hub portion, annular flange, cylindrical portion and plate means bounding said chamber, said cylindrical portion having openings extending radially therethrough; means for mounting said hub portion on said end of said shaft means to position said chamber in fluid communication with said shaft means; a liquid feed assembly including a series of liquid feed means and bridging means, said feed means defining annularly arranged orifices through which liquid discharged through said openings is fed to said material within said container, each said feed means including first and second annular mounting flanges, and at least one orifice bounding annular spacer plate arranged intermediate said mounting flanges, and a first means of said series having a first mounting flange thereof fixed to said annular flange, said bridging means including sleeve members fixed to said second and first mounting flanges of adjacent feed means to space said feed means axially of said cylindrical portion; means to removably clamp said mounting flanges and spacer plate in assembled condition; key means to removably fix at least one other feed means of said series to said cylindrical portion remotely of said annular flange.
 8. An improvement according to claim 7, wherein said key means includes a key bar fixed to the radially outer surface of said cylindrical portion and extending axially thereof and key bar receiving recess formed in said spacer plate of said one other feed means.
 9. An improvement according to claim 7, wherein said second mounting flange of a last feed means of said series is slideably supported by the radially outer surface of said cylindrical portion to form a liquid seal therewith and to cooperate with said first mounting flange of said first feed means to maintain said assembly concentric of said outer surface of said cylindrical portion.
 10. An improvement according to claim 9, wherein said key means includes a key bar fixed to the radially outer surface of said cylindrical portion and extending axially thereof and key bar receiving recesS formed in said spacer plate of said one other feed means; said hub mounting means includes a conically shaped through opening arranged axially of said hub portion, a conically shaped surface portion on said end of said shaft means and bolt means for fixing said hub portion onto said shaft means, said conical surfaces being arranged in a friction tight fluid sealed relationship upon tightening of said bolt means; and said openings being arranged in groups spaced axially of said cylindrical portion in radial alignment with said orifices. 